Electronic torque wrenches are commonly used to apply a desired amount of torque to a work piece, such as a bolt or nut, to ensure proper tightening of the work piece. For example, a mechanic may need to apply 100 ft-lb of torque to separate head bolts of a car. Typically, the mechanic manually sets the torque wrench to the 100 ft-lb setting, which alerts the mechanic when the 100 ft-lb setting is reached for the head bolt that is being worked on. The wrench could also be manually set to alert the user when the work piece is rotated a predetermined angle, for example, 270 degrees. However, often the mechanic miscounts the number of head bolts that were properly tightened or applies the torque wrench to head bolts that have already been tightened, thus leaving some of the head bolts not properly tightened. Moreover, because there is no indication to the mechanic that the desired amount of torque or angular rotation is approaching, the mechanic relies exclusively on the indicator to provide a single indication once 100% of the desired torque is reached, often resulting in over-torque conditions since the mechanic did not realize that the 100% mark was approaching.
Most electronic torque wrenches only include a manual setting, where a user must select a torque or angle setting for each group of work pieces, rather than choosing a preset torque or angle preset into a memory of the torque wrench. The user must therefore input the required torque and/or angular rotation for a desired torqueing operation each time the set of work pieces are acted upon by the tool, thereby introducing the possibility of error through incorrect torque or angle settings input by the user. Some torque wrenches include preset torque and angle targets, but then lack a manual mode and operate only in the preset automatic mode.
Some current torque wrenches also alert the user when the targeted torque is reached within a predetermined tolerance, but such tolerance is not adjustable by the user. More sensitive torqueing operations are therefore subject to the same torqueing tolerances as less sensitive operations. Also, some torque wrenches allow a user to switch between torque measurement and angular measurement modes, to ensure that both the proper amount of torque and amount of angular rotation is applied by the wrench, but these wrenches must be disengaged from the work piece when changing modes, often resulting in inaccurate angular measurements.
There therefore exists a need for a torque application tool that is capable of providing indications to the user when certain levels of the desired amount of torque or angular rotation are reached, thus alerting the user that the desired amount of torque or angular rotation are approaching to lessen the chance of over-torqueing. There also exists a need for a torque application tool that is capable of providing an indication to the user when both the desired torque amount and the desired angular rotation are simultaneously applied to a work piece. There exists a further need for a torque application tool capable of providing an indication to the user when the desired amount of torque is first reached, and then the desired amount of angular rotation is applied to the work piece without removing the tool from the work piece to change from torque measurement to angular measurement modes.